The Scattering of Fast Electrons and Positrons by Heavy Elements

1952 ◽  
Vol 5 (2) ◽  
pp. 258
Author(s):  
EM Gunnersen
Keyword(s):  
Angular Distribution ◽  
Elastic Scattering ◽  
Large Deviations ◽  
Heavy Elements ◽  
Fast Electrons ◽  
Electrons And Positrons

The angular distribution for the single elastic scattering of 1.07 MeV, positrons and electrons by the Hartree field of mercury (Z=80) is calculated. The results show no large deviations from Coulomb values except, possibly, a slight increase in the region of 90� for electrons.

The elastic scattering of fast electrons and positrons by hydrogen and helium atoms

1959 ◽  
Vol 250 (1262) ◽  
pp. 337-345 ◽  
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Born Approximation ◽  
Logarithmic Singularity ◽  
Hydrogen Atoms ◽  
Fast Electrons ◽  
Helium Atoms ◽  
Electrons And Positrons ◽  
Angle Scattering

A simplification of the second Born approximation due to Massey & Mohr is used to calculate the differential cross-sections for the elastic scattering of fast electrons and fast positrons by hydrogen atoms and helium atoms, the method of Dalitz being applied to evaluate all the relevant integrals. Although the logarithmic singularity which is found in the differential cross-section for zero-angle scattering is shown to be absent in the true second Born approximation the use of the simplification of this approximation is justified at sufficiently high impact energies provided the angle of scattering is not too small. The results of the calculations for incident electrons in helium are compared with the available experimental data.

The Elastic Scattering of Fast Electrons by Heavy Elements

1939 ◽  
Vol 56 (6) ◽  
pp. 612-613 ◽  
Author(s):  
J. H. Bartlett ◽  
R. E. Watson
Keyword(s):  
Elastic Scattering ◽  
Heavy Elements ◽  
Fast Electrons

scholarly journals The elastic scattering of fast positrons by heavy nuclei

1942 ◽  
Vol 181 (984) ◽  
pp. 14-19 ◽  
Keyword(s):  
Experimental Investigation ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Nuclear Charge ◽  
Double Scattering ◽  
Heavy Nuclei ◽  
Scattered Intensity ◽  
Fast Electrons ◽  
Theoretical Results

The angular distribution of fast positrons scattered elastically by mercury nuclei is investigated in detail using Dirac’s equations in conjimction with numerical tables provided by Bartlett & Watson for the corresponding fast electrons. The ratio of the scattered intensity to that given by the Rutherford formula is obtained as a function of angle for positrons with energies between 25,000 and 1·7 x 10 6 eV. In all cases the ratio is less than unity, decreases with increasing angle of scattering and, in contrast to electrons, does not depend very markedly on the nuclear charge. The maximum asymmetry produced by double scattering of positrons at 90° from mercury nuclei is less than 1 %. It is suggested that experimental investigation of the scattering of fast positrons would be useful in assisting to resolve the present unsatisfactory situation in which there are a number of outstanding divergences between experimental and theoretical results relating to the scattering of fast electrons.

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

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